General illumination LED system including far UV C

ABSTRACT

An excimer bulb assembly, with an excimer bulb, at least one integral captured reflector, and an integral filter such that the excimer bulb only emits substantial UV radiation between 200 nm and 230 nm, using a filter that passes light from about 200 nm to 234 nm (+/−2 nm).

CROSS-REFERENCE TO RELATED CASES

This application is a continuation of U.S. patent application Ser. No.17/721,693 filed Apr. 15, 2022 which is a continuation of U.S. patentapplication Ser. No. 17/480,990 filed Sep. 21, 2021, now U.S. Pat. No.11,478,563, which is a continuation of U.S. patent application Ser. No.17/459,285 filed Aug. 27, 2021 which is a continuation of U.S. patentapplication Ser. No. 17/193,839 filed Mar. 5, 2021 which is acontinuation of U.S. patent application Ser. No. 17/156,426 filed Jan.22, 2021, now U.S. Pat. No. 11,357,879, which is a continuation of U.S.patent application Ser. No. 17/080,390 filed on Oct. 26, 2020 whichclaims the benefit of U.S. Provisional Application No. 63/069,436 filedAug. 24, 2020, herein incorporated by reference in its entirety for allpurposes.

FIELD OF THE INVENTION

The inventive system is in the field of Ultraviolet Light sterilization,specifically in the C band of wavelengths (UV-C). Such sterilization ispresently used in hospital surgery rooms, burn wards, and similar areasthat require a high degree of sterilization. The primary difference withthese existing uses is the inventive system will be used safely in thepresence of people and living tissues.

BACKGROUND OF THE INVENTION

The Corona Virus pandemic has changed many aspects of human life inevery country. Even after the virus has been tamed by vaccines andantibodies the changes will remain. People are no longer comfortablebeing in close quarters with others in public settings. The contagion ofregular flu and colds are now being treated with many of the sametechniques as were used during the pandemic.

UV has 3 different bands, A, B, and C. UV-A is what we would generallyassociate with “black lights” and black light fluorescence. It is thelongest wavelength of the 3 and has the least ability to kill viruses,bacteria and similar pathogens. Its wavelengths are from 315 nm to 400nm.

UV-B has been the most preferred wavelength to be used by tanningsalons. It is dangerous to use in excess around living things because itis both powerful enough to burn and has a long enough wavelength topenetrate cells, causing irreparable genetic damage. Its wavelengths arefrom 280 nm to 315 nm.

UV-C is recognized as one of the most effective wavelengths at killingthe small pathogens because the shorter the wavelength the more powerfulit is. Only recently was it discovered that some of the wavelengths inthis band are long enough to kill pathogens and short enough to not beable to penetrate living cells. Living cells are many times larger thetiny pathogens that we want to kill. UV-C is from 100 nm to 280 m, andthe wavelengths that are generally being considered safe for exposure tohuman tissue are from 200 nm to 230 nm. UV-C does generate undesirableozone, especially at wave lengths shorter than 200 nm.

Several studies have shown that hairless mice can be subjected to over20 times the amount of 200 nm to 230 nm UV C as is presently suggestedfor humans, 8 hours a day, with no adverse effect. These studies havebeen performed in Japan at University and in the US at ColumbiaUniversity. These studies are extending in time for up to 6 months,still with no adverse effects. Recently humans in Japan were also testedto 250 times the exposure of what is needed to kill 99.9% of pathogensand the test subjects showed no adverse effects, no sunburns, nothing.

There are several technologies that can generate UV light in thegermicidal wavelengths, gas-discharge lamps have been around a long timeand depending on the gases used can kill pathogens. Low pressure mercurygenerates 254 nm and has been the standard for decades, it is basicallya fluorescent light without the phosphors on the inside that convert theUV to visible light. LEDs have recently been commercialized in the UV-Aand UV-B spectrums, but they are very inefficient. There are a few inthe longer wavelengths of the UV C spectrum. A research project in Japanrecently made an LED that was in lower 200 nm's, the safer portion ofthe UV-C spectrum, but it was very inefficient and not practical forcommercialization anytime soon.

Several companies are making UV-C excimer fixtures that emit 222 nm suchas Ushio's 12 W Care222, and another by Eden Park's Flat Excimer Lamps.The Ushio fixture has a flat faceplate filter that is separate from thebulb that blocks all unwanted spectrum that the bulb generates, and thatspectrum is any wavelength longer than about 237 nm. The Eden Parkdevice has no filter attached at this time and consequently emits 25% ofits energy in the dangerous wavelengths from 230 nm to at least 380 nm.

When these filters are not in place then these lights will emit spectrumthat is not safe for living tissue. If a maintenance worker were to tryand replace a bulb they could be exposed to harmful light. If the glassfilter broke or degraded the user would be in danger.

Lastly the materials used are critical. UV-C cannot penetrate plasticsand many glasses, only quartz glass can be used without huge losses ordownright failure to emit the UV-C light. Even nitrogen and moisture inthe air will also absorb or block the UV-C if it is transmitted too farthrough the air.

What is needed is an affordable UV sterilization light that would begood at killing pathogens with no chance to harm, under any situation,humans that would be present.

SUMMARY OF THE INVENTION

The inventive device provides a human-safe UV-C sterilizing bulb thatcan be used in continuous public places. The bulb will be safe in allsituations, efficient, affordable, and could monitor itself and reportconditions.

Studies at Columbia University show that pass filters tuned from 200nm-230 nm kill the pathogens and don't hurt human cells but theinventive device would use 207 nm or 222 nm excimer technology combinedwith an integral band pass filter that would block all spectrum withwavelengths longer than 234 nm. This small change to the filtration adds2.5 times more usable emitted light than the 200-230 nm version and verylittle emissions in the 230-232 nm range. Ushio has products that filterstarting at 237 nm but this risks allowing too much harmful radiation toget through. Ideally the filter material would be deposited directly onthe bulb's envelope, which would be made of quartz glass, and this wouldblock all harmful light even when handled during installation ormaintenance. The 207 nm version requires the gasses bromine (Br) andargon and krypton (Kr). The 222 nm version uses krypton (Kr) andchloride (Cl). The filter material would ideally be very pure hafniumoxide deposited 2˜3 um building a cutoff filter 234-400 nm with a depthof approximately 0.0001. This type of excimer bulb ideally usesDielectric Barrier Discharge (DBD) and this is where the two primaryelectrodes are on the outside of the quartz envelope and in order to getthe gasses to excite requires very high voltages, in the thousands ofvolts. Consequently, the gasses inside of the envelope will not be incontact with any metals that could contaminate them. Some Ushio lightshave one conductor inside the envelope, sort of a hybrid, short-arc/DBDbulb. The inventive device avoids the problems of dissimilar materialsand envelope contamination, and multiple types of glass needed, likeUshio's, by keeping all of the electrodes on the outside of theenvelope. This inventive bulb does need a higher arc voltage but that isa small challenge for all of the benefits that a quartz only envelopesolution provides.

The integral band pass filter could be deposited on a separate piece ofquartz that would be permanently attached to the bulb's envelope usingUV compatible adhesive around the edges. The filter would be integral tothe finished assembly. This would protect users from UV exposure underall conditions including bulb changing and maintenance.

The inventive safe DBD device would also have an integrated capturedreflector on the backside of the bulb's envelope and an additional 2integral mirrors, one on each side of the bulb, set at 45 degrees to thefilter face in order to maximize the light out. Light passing throughthe filter is heavily attenuated if it passes through at any angle otherthan absolutely perpendicular to the filter's plane. Light passingthrough at even 10 degrees from perpendicular is attenuated by 50%,depending on the filter's composition, and the greater the angle thegreater the attenuation and absorption.

The reflector could be a separate material that would be permanentlyconnected to the bulb's envelope using UV compatible adhesive around theedges. The shape of the bulb would ideally be a flattened quartz tubingwhere the two flattened sides are parallel to each other. This designwould be the cheapest and easiest configuration and is scalable. Otherdesirable but less optimum bulb shapes could be a tube-based design thathas a complex shape which would allow the reflector on the back side tobe optimized for different beam angles and patterns. A flattenedcircular tube-based bulb would emit a Lambertian pattern if desired.

The inventive safe DBD bulb will be cartridge based as to be easy toreplace with rigid exposed conductors. The lifetime of 222 nm excimerbulbs is generally about 8000 hours when they lose 10% brightness and itgoes down quickly from there. The high voltages and drivers of excimerbulbs are unique and cannot be connected to other power sources so eachdifferent bulb power/size will need a unique connector to avoidconnections between electrically incompatible parts and polarizationwould be desirable as well. The primary high voltage electrode wouldideally be a conductive ink made of silver or similar conductive metalsprinted in a mesh pattern over the non-opaque or filter area. The secondprimary electrode would also be at 0 volts and use the conductive ink asthis would reduce parts. Because of the high voltages used in excimerbulbs a safety cutoff switch should be included in the inventive fixturein the case of a maintenance worker opening the fixture to safelyreplace a bulb.

Such a safe bulb will also have a built-in smart chip that hasnon-resettable serial number, manufacture date, use date, temperatureboundary, and a Hobbs meter or hour meter. The smart chip would ideallyuse encryption in order to not be hacked. The bulb's fixture will be incommunication with the smart chip on the bulb, and the fixture will haveInternet Of Things (IOT) connectivity. The bulb's fixture will monitorthe bulb life and when it was first turned on and shut down the bulb, ifit or is it running over temperature, if it is near to end of life? Thiswill protect the users in case the filters begin to degrade, or thelight intensity is not up to specification. It can notify or be polledby maintenance software and request replacement. The IOT connection canbe used to talk to remote sensors that measure the output at differentlocations around the fixture's environment, where people are exposed.Because this type of bulb does not emit much visible light the fixtureshould include a multicolored LED indicator so that users can quickly ata glance know that the fixture is working, or not working properly.

Because the light output degrades over time and the inventive safefixture has feedback as to the environment's light level the fixturecould boost the output over time to have a constant output level. Thefixture would ideally have a light sensor to determine light output. Theoutput level could be estimated by time used and that table could beprogrammed into the fixture so that the fixture could be constantlyincreasing the output power for a near-constant lumen output, or atleast a good estimation.

When emitting a light that kills germs and the public is exposed to it,absolute safety is the primary standard that has to be met, tested andverified. The safeguards built into this fixture should not be luxuries,but should be requirements to allow a UV-C light to be exposed to thepublic.

When entering an area that is protected by the inventive device, thepublic should have access to the assembled data. They might ask, “Howlong is the kill time for pathogens on surfaces, in the air? At whatpercentage output is the system running at? How much time can a humanspend in this environment per day?”

The nature of DBD excimer bulbs is that the gasses can overheat and thatcauses the lighting level to diminish so proper cooling is arequirement. The inventive safe bulb could have a ceramic or metallicheatsink on the back side. The envelope could also be extruded withlinear fins to add surface area for convection cooling, similar to howan aluminum heat sink is designed. The fins would be on the outside ofthe light emitting envelope. A fan could blow air on the bulb in orderto lower the gas temperature, especially when the power level is raised.A temperature sensor could part of the bulb to give temperature feedbackand the fan's speed could be regulated as to have a constant envelopetemperature.

Another reality of excimer bulbs is that they sometimes are hard tostart in cold conditions and they need coiled filaments, resistors, orsimilar heating elements to preheat the gasses. These could be used topreheat the safe UV-C bulb at cold or even at normal start-ups and couldbe either inside or ideally outside the quartz envelope or encased inthe ceramic heatsink. The power supply in the fixture would have to haveadditional circuitry to enable this feature. The inventive fixture woulduse pulse square wave rather than sine wave to drive the bulbs. Sinewave power for these high voltage applications are the standard but allof the energy below the peak voltage of the sine wave does not convertto light, it only makes heat.

The inventive safe device can use either 222 nm or 207 nm chemistries orboth. Using two separate envelopes would allow tailoring the specificwavelength to best kill an emerging pathogen. Each chemistry hasdifferent drive voltages and arc gaps, but a power supply could easilybe configured to drive either or both simultaneously. Ideally theinventive device will use DBD where the electrodes are on the outside ofthe glass envelope. This type of discharge requires very high voltagesto get the gasses inside to excite but using this technique the gassesinside the envelope are never contaminated by electrode erosion, acommon problem in gas discharge lamps when used over time.

The inventive safe bulb would be used in environments where there isregular visible light coming from light fixtures and the inventive bulbcould be combined with traditional light sources in a single fixture. Ifthere was any adverse visible color emitting from the UV-C portion ofthe fixture the visible light's spectrum could be modified and mixed insuch a way as to normalize the mixture or average of color coming fromthe fixture. This type of fixture would ideally be a “can”, the type offixture that is installed in a round hole in a ceiling.

The inventive safe system could be packaged as a typical light bulb. Theballast or power supply could be fitted in the base and the bulb wouldshine omnidirectionally, just like an LED or compact fluorescent lightbulb, and it could have conventional lighting included as well.

The foregoing has outlined in broad terms the more important features ofthe invention disclosed herein so that the detailed description thatfollows may be more clearly understood, and so that the contribution ofthe instant inventors to the art may be better appreciated. The instantinvention is not limited in its application to the details of theconstruction and to the arrangements of the components set forth in thefollowing description or illustrated in the drawings. Rather theinvention is capable of other embodiments and of being practiced andcarried out in various other ways not specifically enumerated herein.Additionally, the disclosure that follows is intended to apply to allalternatives, modifications and equivalents as may be included withinthe spirit and the scope of the invention as defined by the appendedclaims. Further, it should be understood that the phraseology andterminology employed herein are for the purpose of description andshould not be regarded as limiting, unless the specificationspecifically so limits the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 Low pressure mercury bulb (prior art) line drawing from photo

FIG. 2 Ushio Care222 excimer bulb and driver (prior art) line drawingfrom photo

FIG. 3 Eden Park's Flat Excimer Lamp (prior art) line drawing from photo

FIG. 4 Spectrum graph of a 207 nm Br Kr emission

FIG. 5 Spectrum graph of a 222 nm Kr Cl emission

FIG. 6 Spectrum graph of a 207 nm Br Kr emission with proper filtration

FIG. 7 Spectrum graph of a 222 nm Kr Cl emission with proper filtration

FIG. 8 Drawing of basic bulb

FIG. 9 Exploded isometric drawing of bulb assembly

FIG. 10 Side view section of bulb assembly

FIG. 11 Isometric view of bulb cartridge

FIG. 12 Exploded view of multi-bulb fixture

FIG. 13 Depiction of fixture aiming down with bulbs aiming straight down

FIG. 14 Depiction of fixture aiming down with bulbs aiming out at 45degrees

FIG. 15 Safe bulb heat sink with heating filament

FIG. 16 Safe Bulb with both UV-C and general illumination elements

FIG. 17 Temperature regulated fixture with fan-cooled safe bulb

FIG. 18 Block diagram of a fixture including driver, bulb, temperaturesensor, and safety cutoff switch in a fixture

FIG. 19 Network diagram of IoT bulb and system

FIG. 20 Depiction of the output of a pulse wave power supply compared toa sine wave

FIG. 21 Depiction of the output of a pulse wave power supply at fullpower and during dimming

FIG. 22 Depiction of a single-phase dielectric fluid cooled UV C bulb

FIG. 23 Depiction of a liquid cooled high power excimer bulb of thepresent disclosure

FIG. 24 A block diagram of a liquid cooled bulb of the presentdisclosure with a coolant system resulting in a high powered excimerfixture

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments herein and the various features and advantageous detailsthereof are explained more fully with reference to the non-limitingembodiments that are illustrated in the accompanying drawings anddetailed in the following description. Descriptions of well-knowncomponents and processes and manufacturing techniques are omitted so asto not unnecessarily obscure the embodiments herein. The examples usedherein are intended merely to facilitate an understanding of ways inwhich the invention herein may be practiced and to further enable thoseof skill in the art to practice the embodiments herein. Accordingly, theexamples should not be construed as limiting the scope of the claimedinvention.

Before explaining the present invention in detail, it is important tounderstand that the invention is not limited in its application to thedetails of the construction illustrated and the steps described herein.The invention is capable of other embodiments and of being practiced orcarried out in a variety of ways. It is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and not of limitation.

Referring now to the drawings, wherein like reference numerals indicatethe same parts throughout the several views, a representative depictionof an (existing art) Low pressure mercury bulb 100 shown in FIG. 1 .Where bulb 100 has several parts, the electrical contact points 102 and104, the metal support structure 106, the primary electrode 108, themercury and argon gas 110, the outer envelope 112, tip support 114, thestriking electrode 116, a resistor 118, a glass base 120, and the secondprimary electrode 122.

A newer and different technology is shown in FIG. 2 where an UshioCare222 excimer bulb and driver system 200 is shown in block diagramform. The bulb 202 is driven by the driver 204 through 2 wires 206 and208. The bulb has two primary electrodes 210 and 212. Housings andfilters are separate and not shown.

The next drawing in FIG. 3 shows a flat version of an excimer bulb thatis Eden Park's Flat Excimer Lamp 300. It has two narrowly spaced flatsheets of quartz glass 302 and 304 with electrodes 306 and 308 on theoutside of the front 310 and back 312 plates. The bulb has no filter orreflector.

In FIG. 4 a spectral graph is shown of a 207 nm Br Kr emission 400. Theprimary emission spike 402 at 207 nm is a safe wavelength for humantissues and is deadly to small pathogens such as viruses and bacteria.Also shown is a small amount of emission at 230 nm 404 which is atdangerous edge of spectrum incompatible with human exposure. Shown isadditional emission at 270 nm 406 which even at this low level isextremely dangerous to human exposure. Lastly a spike of emission at 290nm 408 and it is not safe for human exposure.

In FIG. 5 there is a spectral graph of a different chemistry than whatwas shown before, this 222 nm Kr Cl emission 500. The primary emissionspike 402 at 222 nm is a safe wavelength for human tissues and is deadlyto small pathogens such as viruses and bacteria but it continues at alow level into the deadly 240 nm 504 range. There is also a small bumpof emission at the 260 nm range 506 and this is extremely dangerous evenat such a low level.

In FIG. 6 a spectral graph is shown of a safe 207 nm Br Kr emission 600with a spike at 207 nm 602. 207 nm is a safe wavelength for humantissues and is deadly to small pathogens such as viruses and bacteriaand due to subtractive filtering, there is no emissions in the dangerouswavelengths.

In FIG. 7 a spectral graph is shown of a safe 222 nm Kr Cl emission 700with a spike at 222 nm 702. 222 nm is a safe wavelength for humantissues and is deadly to small pathogens such as viruses and bacteriaand due to subtractive filtering, there is no emissions in the dangerouswavelengths.

In FIG. 8 an inventive excimer bulb 800 is shown. The bulb 800 has aquartz envelope 802 that contains a combination of gases at about 300millibar pressure, depending on the specific chemistry involved, Br Krat 207 nm or Kr Cl at 222 nm. The two flattened sides are parallel toeach other and are approximately 10 mm apart, but this varies withdifferent power levels, fill pressures, and drive voltages.

The quartz envelope 800 starts as a round cylinder and is heated andpulled through rollers that flatten the two sides, the front face 802,and the back face 804 to be parallel with each other. The ends of theflattened tube are then sealed at both ends 806 and 808 by heat weldingto seal them. The fill point 810 as shown starts as a small fill tubethat is melted shut after the bulb has been cleaned and filled with thelow-pressure gasses. The sides of the bulb 812, and 814 allow light topass as well, the right side 812 and the left side 814. These pathwaysof light have been ignored by prior art devices and enormous amount ofwasted optical energy will be harnessed here by the inventive device.

In FIG. 9 depicts an exploded view of a safe flattened tube design bulbassembly cartridge 900. Starting at the bulb 800 as the center of theassembly. The front electrode 902 is the ground, or 0 Volt, electricalgrid and it is placed directly against the quartz bulb's face 802. Itcan be made of a non-corroding conductive metal such as molybdenum orsilver. Ideally this front grid 902 or screen will be closest to theuser and that is why the ground, or 0 Volt, potential was chosen forthis side. To eliminate ozone production the grid would be applied as aconductive liquid or ink to eliminate oxygen from the electrical path.Similarly, the rear electrode 904 is the positive electrode. It too isplaced directly against the quart envelope's back side 804. The voltageon this side is approximately 10,000 Volts and is placed away from theuser as possible. This electrode 904 would be plated on or applied as aconductive ink to eliminate oxygen from getting between the conductiveelectrode and the path of high voltage electricity.

A rear reflector 908 is added against the outside of the rear electrode904. The rear reflector 908 and the rear grid 904 could be combined asone part to both conduct electricity and reflect light, and as suchcould be a vapor plated on aluminum layer which would be depositeddirectly to the back side face 804 of the bulb 800 to further minimizeparts and costs. Side reflectors 926, and 928 are set at 45% angles inorder to capture light that escapes the sides 812 and 814 of the bulb800 and send it directly forward and parallel to the light that is beingemitted by the main face 804 of the bulb 800. Spaced as closely aspossible to the two side reflectors 926 and 928 and the front electrode902 is the UV filter plate 906 which is made of polished quartz andplated layers of Hafnium Oxide that form a narrow band pass filter inthe 200 nm-234 nm range.

A heatsink 910 which could be aluminum but ideally would be ceramic toadd electrical insulation to the high voltage back electrode 904. Theheatsink 910 will block any unfiltered light from emitting throughcracks between the mirrors 908, 926, and 928 or out of the ends of thebulb 800. Ideally the heatsink 910 would also capture many of theindividual elements of the bulb assembly mentioned so far including thebulb 800, the rear reflector 908, the side reflectors 926 and 928, therear electrode 904, the front electrode 902, and the front filter plate906 and it would be tightly sealed using UV compatible epoxy would beused around the edges of the bulb 812 to stabilize the mechanicalconnections between these components and completely seal air and dustincursion. Existing art designs allow for air to be blown directly overthe bulbs and dust could then deposit over time to the bulbs and theinside face of the filter. Dust can absorb large amounts of the UV Clight and become very inefficient very quickly. The inventive deviceeliminates these faces from dust incursion by making a sealed cartridge900 using the end caps 912 and 914. These end caps 912 and 914 of thebulb assembly 900 will be made of ceramic and the end cap 912 wouldencapsulate thermal sensors and a smart chip 916, as well as provide amechanical rotation point for the bulb including detents 918 for presetindividual position stops in a fixture. This means a light emittingcartridge that has no wires or flying leads to connect. The smart chipand temperature sensor 916 has an hours of operation meter, serialnumber, manufacturing date, temperature, out of range flags, andencryption communication capabilities to prevent counterfeit operation.There as a conductive jumper 930 in connection with the front electrode902 that passes through the ceramic end cap 912 and then is electricallyconnected by to a conductive pin 920. Similarly, there is a conductivejumper 932 that is in connection to the rear electrode 904 that passesthrough the ceramic end cap 914 and then is electrically connected to aconductive pin 922. There are 3 plated-on conductive traces 924 aroundthe ceramic end cap 912 that are connected to the smart chip and thermosensor 916. These traces 924 allow communication from the bulb cartridge900 to contacts on the fixture receiver to allow the fixture tocommunicate with these chips 916. Such mechanical and electricalconnections are well understood by one skilled in the art and othermethods of connectivity could be used. This assembly becomes an easy toreplace safe UV C bulb cartridge 900 that is hermetically sealed withall high voltage portions insulated and removed from those who handle itor are exposed to it.

FIG. 10 depicts a sectioned side view of an assembled safe UV-C bulbcartridge 900. The bulb 800 has the negative electrode 904 plated orapplied directly to the quartz. Similarly, the positive electrode 902applied directly on the bulb's 800 front face 804. Behind the negativeelectrode 904 is the rear reflector 908. The right-side reflector 926and the left side reflector 928 are angled at 45 degree angles to thefront face 804. They are all captured and contained by the ceramicheatsink 910. There is a tiny air space between the bulb 800 and thefilter 906 that is sealed by the ceramic pieces and ideally UV tolerantsealant.

FIG. 11 depicts an assembled safe UV-C bulb cartridge 900. The assembledcartridge 900 has an optical aperture 1102 that is sealed around theedges such that air and dust and unfiltered light are eliminated frompassing through.

FIG. 12 shows an exploded view of a multi-cartridge variable beam anglefixture 1200. Each of the 3 bulb cartridges or heads 900 ride in ceramicsaddles 1218 that have conductive spring clips 1220 that retain themetallic pins 920 and 922 of the bulb cartridges 900 as well as connectpower to bulb cartridges 900. The saddles 1218 and corresponding endcaps 912 at one end are a different size than the saddle 1218 and endcap 914 at the other end which allows polarizing the ends so that thebulb cartridge 900 can only be inserted one way and the zero voltagepotential 902 is always on the front face and the high voltage potential904 is always on the back side, away from users.

The saddles 1218 also hold detent springs 1216 which mate with detentridges and groves on the bulb end caps 912 and 914. This allows the bulbcartridges 900 to have several exact angles that they can easily be setto, the spring 1216 holding them 900 in each position but allowingfinger pressure to allow it to snap to the next detent position. Thefront bezel 1222 of the fixture swings away from the base 1202 by meansof a latch and hinged connection 1208 between the front bezel 1222 andthe rear housing 1202 to expose the bulb cartridges 900 for maintenanceor replacement. When the front bezel 1222 is closed completely itpresses against a safety switch 1210 which is mounted in the rearhousing 1202, the pressed microswitch 1210 then enables power to thefixture 1200. Proximity and distance checking is also determined bydistance sensor 1214 which looks through a small hole in the bezel 1222and checks distance to the closest object or floor. The safety switch1210, distance sensor 1214 and data from the 3-bulb cartridge's smartchip and thermo sensors 916 are all connect to and coordinated by thesmart power supply 1204. The power supply 1204 also has digitalcommunication capabilities such as Wi-Fi and Ethernet to name just acouple. Air is pulled through perforations in the front bezel 1222 by afan 1206 that is supported by a fan frame 1224 then blows this air overthe top of the power supply 1204 and over the bulb cartridge's heatsinks910 and out through holes in the base 1202. The power supply 1204measures bulb cartridge 900 temperatures and modifies the fan 1206 speedfor optimum efficiency of the bulb cartridge 900 efficiency. A mountingplate 1226 is capable of mounting first to standard electrical boxesfound in existing architectural situations and then the plate snaps tothe rear housing and can spin in the rear housing tracks to allow theupper bezel to aim in infinite directions. Because UV C light filterstend to allow light to only pass at narrow angles the emitted lighttends to be in a narrow beam. This inventive fixture allows for multipleheads in a single fixture to allow for wider beams and asymmetricallight dispersion to best fit the widest range of environmental confines.Ideally the fixture would have an illuminated indicator 1228 to showfunctions and or faults from a distance, in the illustration theindicator 1228 is a backlit logo. The preferred embodiment shows 3 bulbsin a fixture 0but any number of bulbs could be used in the inventivedevice.

In FIG. 13 Depiction of fixture aiming down with bulbs positionedstraight down 1300. Fixture 1200 has 3 bulb cartridges 900 aimedstraight down 1302 for a tight beam angle under the fixture 1200. Thisforms the narrowest beam possible for the fixture and would be used insituations where there is a very high ceiling or where the emitted lightneeded to be concentrated.

In FIG. 14 Depiction of fixture aiming down with bulbs positioned at 45degrees 1400 where fixture 1200 has 3 bulb cartridges 900 aimed out at45 degrees each 1402. The wide beam angle under the fixture 1200 andwould be used on lower ceilings or in areas with a very wide area to becovered.

In FIG. 15 Depicts a safe bulb heat sink with a heating filament 1500.The heatsink 910 can be modified to have a heating element 1502 that ispermanently installed through a hole in the heatsink or is simplyembedded in the ceramic along its long axis. This heated heatsink 1500will conduct heat to the bulb 800 and warm the gases inside making themable to ignite when requested. Electrical heating elements 1502 are over100 years one hundred years old and well understood by one skilled inthe art. This heating element 1502 is controlled by the smart powersupply 1204 when needed to start the fixture 1200 during coldconditions. Once the bulbs 900 are operating they warm up and theheating element 1502 can be turned off. Extra electrical contacts wouldbe required for this inventive addition to the excimer bulb assembly.

FIG. 16 depicts a side view of a screw-in UV-C safe bulb 1600. For meansof illustration only this depiction uses a flood light type bulb 1602but any type of screw in bulb would be applicable regarding thisdisclosure and this disclosure is not meant as a limitation in any way,just one example. The safe bulb with both UV-C and general illuminationelements 1600 is placed inside a screw-in bulb housing 1602. Thetraditional electrical contacts of said screw-in bulb 1612 and 1614 goto the driver/power supply 1204. The driver/power supply 1204 thenpowers the UV-C portion 900 of the safe bulb with both UV-C and generalillumination elements 1604 through wires 1606 on circuit board 1616 thewires go to clips mounted on the circuit board, the clips were not shownfor simplicity. The driver/power supply 1204 also powers separately thewhite LED 1604 portion via wires 1608. The translucent face 1610 ofscrew-in UV-C safe bulb 1600 needs to be made of quartz glass, ideallywith a diffused surface such as sandblasting or other texture. UV-Cwould be absorbed by any plastic or traditional glass cover. Theinventive flattened cylinder bulb 900 is combined on a circuit board1616 with a number of LEDs 1604. The LEDs could all be one color ofwhite or they could be a mix of colors or different color temperatureswith individual LED 1604 control to mix LEDs 1604 of different colors.The color of light emitted by just the safe UV-C portion of thisinventive device will not be optically bright to the human eye, and itwill also include a pinkish purple cast. The white LEDs could be pink orpurple deficient so that when both the safe UV-C and white LEDs areturned on, the combined light would have a neutral color spectrum.

FIG. 17 depicts fixture with a temperature regulated fan-cooledflattened cylinder safe UV-C bulb fixture 1700. The smart power supply1204 is in communication with the smart chip 916 in the bulb 900 throughthe low voltage data lines. Above the heatsink 910 is a small muffin fan1206 that blows down on the heatsink 910 and bulb 900. The fan iscontrolled and powered by driver/power supply 1204. The thermal sensor916 encased inside the ceramic base is interrogated by the smartdriver/power supply 1204. Based on the power being sent to the bulb 900and the reported temperature the driver/power supply 1204 will drive thefan 1206 to an appropriate speed in order to regulate the temperature ofthe bulb 900 in a closed loop. The heatsink 910 may or may not benecessary because lower powered bulbs would not need the heat sink 910,higher powered bulbs might need a big heatsink or a pin-fin heatsink910, by example and not by limitation. The driver/power supply 1204 willalso power resistive heaters when the bulb 900 has not been on and thethermal sensor detects that bulb ignition might not be possible due tolow temperatures. The driver/power supply 1204 would then power theresistive heater before applying power to the bulb 900. Later once thebulb 900 was operating the driver/power supply 1204 might have to powerthe fan 1206 to cool down the bulb 900. The power supply powers theexcimer bulb using pulse wave high voltage DC power in the inventivefixture. The width of the individual pulse waves can be altered tocontrol brightness of the bulb 900 or some of the pulse waves can simplybe skipped to dim the light's output. Most excimer bulbs are presentlydriven by sine wave power supplies and they have too much un-harvestableenergy below 9,000 volts. This energy simply heats the envelope anddoesn't generate light. The pulse wave may have a bit of a rounded topbut otherwise looks like a square wave, it has straight sides, nounusable power. The bulb's predicted output over time can be programmedinto the power supply so that as the hour meter in the bulbs age andreport, the power supply could raise the power slightly to compensatefor the lower efficiency to have a constant lumen output over time.

FIG. 18 is a block diagram of driver, bulb 900, distance and proximitysensor 1214, light level sensor 1224, smart chip 916 and safety cutoffswitch 1210 in a fixture enclosure. The bulb 900 is connected to thedriver/power supply 1204. The driver/power supply 1204 has a switch 1210wired to the door or front bezel 1222 of the fixture enclosure so thatwhenever the door 1222 is open, power to the bulb 900 is turned off.This is an especially important safety issue because excimer lights canoperate using several thousand volts. The driver/power supply 1204 talksto the smart chip 916 and verifies that this bulb 900 is valid and hasnot been tinkered with and is a valid replacement via communication withthe smart chip. Counterfeit bulbs would most likely not have thepass-filter and would emit dangerous wavelengths towards the user. Thedistance/proximity sensor 1214 makes sure that the output power level isappropriate for the distance to the ground and could change the outputpower lever to the bulbs based on the distance. The proximity sensor1214 and smart power supply 1204 look to lower power levels or turn offif it detects objects at very close distances such as a maintenanceperson trying to work on the fixture 1200. The proximity sensor anddistance sensor 1214 could be the same sensor. The UVC light levelintensity sensor 1224 could either look at the ground or at the bulb. Itwould be filtered to only see 200 nm-230 nm wavelengths. It coulddetermine total light output and the smart power supply/driver could usethis information to adjust the output for constant lumen output. Smartfunctions of the power supply 1204 could be moved to a separate circuitboard and that board could then control the power supply 1204. Suchfunctions are well known by one skilled in the art.

FIG. 19 Is a network diagram of IoT bulb and system 1900. The inventivedevice 1200 may have LEDs 1228 on the basic light fixture 1200 that willindicate that it is on and disinfecting. This could be a constant LED1228 or intermittent LED 1228. Similar to a smoke detector, the light1200 will be “good” or “OK” in one color IE Blue or Green whenfunctioning properly and will turn to “attention” or “error” in anothercolor IE Amber or Red. The indicator 1228 could be in the form of abacklit logo.

People entering a room can quickly look and see that the light 1200 isfunctioning or needs maintenance by looking at the LED 1228. The led1228 may also indicate output level. When there is low activity and lowbacterial load events it could have one LED on, when there is highactivity with increased bacterial load events, the light increasesoutput and the LEDs 1228 will change to signal this event. The fixturecould receive data from crowd density sensors and use this informationto set the output power levels.

Crowd density sensors 1906 such as CrowdScan 1906 an rf monitor fromAntwerp or Density 1906 which is a Lidar based device from San Franciscohave the ability to determine how many people are in a given space at agiven time without violating their privacy, i.e. using cameras or cellphone snooping techniques. There are several more services similar tothese which are simply examples of crowd density sensors 1906 thatcommunicate as IoT 1906 and internet resources such as the inventivedevice 1900.

The light 1200 may integrate several different kinds of communication1904 to include BlueTooth 1904, WiFi 1904, Cellular 1904, Sidewalk 1904from Google, and hard-wired technologies 1904 to mention a few. Thiscommunication 1904 will allow for the monitoring of the light functionand allow remote control of the light by remote means.

The light 1200 may have local mechanical control systems such as simpleon/off and dimmable light switches. The light(s) 1200 may also have acontrol panel with switches and LEDs to control many lights. The LEDs inthe panels can show status or light (on, off, status, etc.). Theinventive device lights 1200 can be integrated with other traditionalvisible/functional lighting. These physical controls would allowcontrols over those lights also. Physical controls can vary depending onthe light fixture application. For applications the fixture 1200 isinstalled permanently in a space the controls can be integrated into thefacility infrastructure. For stand-alone portable applications thecontrols may be fully integrated into a light 1200 to include integratedpower source with power level indicators and a graphic user interfacedisplay and control panel.

The light fixture 1200 can communicate 1904 to facility/installationmanagers and operators. The information can be accessed by a smartphoneapplication 1906, web interface on a laptop 1908 or desktop 1908. Thefixture 1200 will push information to the site and the operator can pullinformation from the light 1200. The wireless interface can becustomized for different users' needs. The light 1200 can communicatewhat output level it is at, what the energy consumption level is,internal temperature, lifecycle/hours the bulb 900 has been in use andhow long till it will need to be replaced, work in combination withmotion detection to determine if there is a high bacterial load in thespace it is set up in. The operator can also control the level of thelight 1200 output and schedule the operation profile customizable tobest sterilize the area and optimize energy consumption.

The light fixture 1200 can communicate the status to the public or spaceoccupants. The information can be accessed by a smartphone 1906application, web interface on a laptop 1908 or desktop 1908. This willreassure occupants that the space is being sterilized. The informationcan also be displayed on an information display in the space.

FIG. 20 is a diagram showing a couple of the power pulse trains used fordriving excimer bulbs and showing the differences between 10,000 voltsine wave 2002 power compared to 10,000 volt pulse wave 2006 power. Onlythe top voltages between 9,000 and 10,000 volts which are shown in thelight areas make usable light. All voltages below 9,000 volts simplymake heat and that heat minimizes the power level that a bulb can bedriven to. The dark area 2004 between the outline of the sine waves andthe center white areas are all wasted power and turns to heat that isgenerated inside the bulb that does not come out as light. There is nowasted voltage in the pulse wave power supply example. The inventivedevice 1200 would ideally use pulse wave power 2006 in its power supply1204. This should provide a 50-100% increase in bulb efficiency over theexisting sine wave based UV C fixtures. It is also possible to lower thevoltage of the pulse wave 2006 below 10,000 volts to dim the bulb's 800output. The voltage range based on the supplied graph would be 100% at10,000V and 0% at 9,000V, which is a very narrow voltage range that hasto be modified and controlled.

FIG. 21 is a diagram showing the power pulse train 2100 for drivingexcimer bulbs where the pulse wave 2102 is at 100% and a pulse wave 2104at 50% dimming using a symmetrical pattern by reducing every other wave,and a pulse wave 2406 at 50% dimming using an asymmetrical pattern. Thepower supply simply has to remove individual pulses to reduce brightnessand because the pulses are so fast, between 10 k Hertz and 250 k Hertzsmall dropouts are not obvious and the amount of visible light generatedis negligible even at 100%. The smart power supply has a microprocessorthat subtracts some of these pulses to dim the fixture's output to anylevel down to 1% or lower. This technique is well understood to thoseskilled in the art. These graphs are for examples only, the actualvoltages will vary with bulb design and internal gas compositions.

FIG. 22 Shows a side view depicting an excimer bulb 800 with variablefocus as a system 2200. The bulb 800 has positioned in the light path2202 a quartz lens 2204 with light shaping capability. The lens 2204 canbe round and symmetrical or linear to best match the initial opticalpath 2202. The lens 2204 could also be continuous or a Fresnel which isstepped. The lens 2204 can be moved closer or further to the excimerbulb 800 to change the focus and spread or narrow the beam angle of thefinally emitted light 2206. This drawing is simplified and does not showfilters or mirrors or other mechanical components that were previouslymentioned, for the sake of clarity of the bulb to lens relationship.

FIG. 23 Shows a liquid cooled high power excimer bulb 2300. It consistsof an outer envelope 2302, and an inner envelope 2304, where the outerenvelope 2302 is shorter and the inner 2304 is longer and they areconnected by 2 end caps 2306 which are welded together by heat. The areabetween the inner and outer has a fill point 2308 on one of the end caps2306. The fill point 2308 similar to those on existing excimer bulbs andthis form chamber 2318 between the two envelopes is evacuated an filledwith the appropriate excimer gasses previously mentioned, through thefill point 2308. The outer wall 2310 of the outer envelope 2304 has aconductive grid 2312 adhered to it and it becomes the negative electrodewhich goes all of the way around the circumference of the tube 2304.Similarly the inner wall 2314 of the inner tube 2304 has a conductivegrid 2316 which goes around its inner circumference and becomes thepositive electrode. Light exits equally in all directions from this typeof bulb.

FIG. 24 Shows a block diagram for a liquid cooled bulb 2300 with thecoolant system which results in a high powered excimer fixture 2400. Thebulb 2300 has a tube 2412 connected to the input end 2402 that connectsto a pump's 2404 output. The pump's input is connected to a return loop2406 of tubing which goes out and around to the output end 2408 of thebulb 2300. Inside of the tubing 2406 and the pump 2404 and the innerwall 2316 is a single phase dielectric liquid which is circulated usingthe pump 2404. This dielectric liquid 2410 is typically used in largedata centers where the entire server is submerged in a vessel to coolthe server components. The liquid 2410 conducts heat very well but isnot electrically conductive which is a very important characteristic forthe inventive device 2400, the liquid 2410 will be in contact with the10,000 volt conductive mesh 2316 of the bulb 2300. Heat is generated inthe interior 2318 of the bulb 2300 and this heat is carried away by thepump 2404 and it dissipates to the environment during its trip throughthe return loop 2406 before reentering the pump 2404, where therecirculation continues. The return loop 2406 might include a separateradiator 2406 similar to what is used in the computer cooling industry,this is well known to those skilled in the art. The power supply 2414 isconnected to the bulb 2300 using the negative wire 2416 which connectsto the exterior mesh 2312. The power supply 2414 also connects to thebulb 2300 using the positive wire 2418 which connects to the inner mesh2316 and is in contact with the coolant 2410. The cooling 2410 allowsfor much more power to be introduced to the bulb 2300 allowing for anunmatched and powerful excimer fixture 2400.

It is to be understood that the terms “including”, “comprising”,“consisting” and grammatical variants thereof do not preclude theaddition of one or more components, features, steps, or integers orgroups thereof and that the terms are to be construed as specifyingcomponents, features, steps or integers.

If the specification or claims refer to “an additional” element, thatdoes not preclude there being more than one of the additional element.

It is to be understood that where the claims or specification refer to“a” or “an” element, such reference is not be construed that there isonly one of that element.

It is to be understood that where the specification states that acomponent, feature, structure, or characteristic “may”, “might”, “can”or “could” be included, that particular component, feature, structure,or characteristic is not required to be included.

Where applicable, although state diagrams, flow diagrams or both may beused to describe embodiments, the invention is not limited to thosediagrams or to the corresponding descriptions. For example, flow neednot move through each illustrated box or state, or in exactly the sameorder as illustrated and described.

Methods of the present invention may be implemented by performing orcompleting manually, automatically, or a combination thereof, selectedsteps or tasks.

The term “method” may refer to manners, means, techniques and proceduresfor accomplishing a given task including, but not limited to, thosemanners, means, techniques and procedures either known to, or readilydeveloped from known manners, means, techniques and procedures bypractitioners of the art to which the invention belongs.

The term “at least” followed by a number is used herein to denote thestart of a range beginning with that number (which may be a rangerhaving an upper limit or no upper limit, depending on the variable beingdefined). For example, “at least 1” means 1 or more than 1. The term “atmost” followed by a number is used herein to denote the end of a rangeending with that number (which may be a range having 1 or 0 as its lowerlimit, or a range having no lower limit, depending upon the variablebeing defined). For example, “at most 4” means 4 or less than 4, and “atmost 40%” means 40% or less than 40%. Terms of approximation (e.g.,“about”, “substantially”, “approximately”, etc.) should be interpretedaccording to their ordinary and customary meanings as used in theassociated art unless indicated otherwise. Absent a specific definitionand absent ordinary and customary usage in the associated art, suchterms should be interpreted to be ±10% of the base value.

When, in this document, a range is given as “(a first number) to (asecond number)” or “(a first number)-(a second number)”, this means arange whose lower limit is the first number and whose upper limit is thesecond number. For example, 25 to 100 should be interpreted to mean arange whose lower limit is 25 and whose upper limit is 100.Additionally, it should be noted that where a range is given, everypossible subrange or interval within that range is also specificallyintended unless the context indicates to the contrary. For example, ifthe specification indicates a range of 25 to 100 such range is alsointended to include subranges such as 26-100, 27-100, etc., 25-99,25-98, etc., as well as any other possible combination of lower andupper values within the stated range, e.g., 33-47, 60-97, 41-45, 28-96,etc. Note that integer range values have been used in this paragraph forpurposes of illustration only and decimal and fractional values (e.g.,46.7-91.3) should also be understood to be intended as possible subrangeendpoints unless specifically excluded.

It should be noted that where reference is made herein to a methodcomprising two or more defined steps, the defined steps can be carriedout in any order or simultaneously (except where context excludes thatpossibility), and the method can also include one or more other stepswhich are carried out before any of the defined steps, between two ofthe defined steps, or after all of the defined steps (except wherecontext excludes that possibility).

Thus, the present invention is well adapted to carry out the objects andattain the ends and advantages mentioned above as well as those inherenttherein. While presently preferred embodiments have been described forpurposes of this disclosure, numerous changes and modifications will beapparent to those skilled in the art. Such changes and modifications areencompassed within the spirit of this invention as defined by theappended claims.

What is claimed is:
 1. A fixture to illuminate an occupiable space,comprising: at least one LED adapted for general illumination of atleast a portion of the occupiable space; at least one krypton chlorideexcimer light source adapted to irradiate at least a portion of theoccupiable space with Far UV radiation; at least one power supply; saidat least one power supply adapted to provide at least 2000 volts with afrequency of at least 10 k Hz to said at least one krypton chlorideexcimer light source; a quartz aperture; a pass filter that has at leastone layer of hafnium; said at least one LED in communication with saidat least one power supply; said at least one power supply adapted forelectrical communication with the fixture.
 2. The fixture of claim 1wherein said at least one power supply is adapted to control said atleast one LED separately from said at least one Far UV light source. 3.The fixture of claim 1 wherein said at least one LED is white.
 4. Thefixture of claim 1 wherein said at least one LED is more than one LEDand more than one color.
 5. The fixture of claim 1 wherein the fixtureis a can light.
 6. The fixture of claim 1 including an IoT interface. 7.The fixture of claim 1 including a diffusion layer.
 8. The fixture ofclaim 7 wherein said diffusion layer is adjacent said quartz aperture.9. The fixture of claim 1 further including a proximity sensor.
 10. Thefixture of claim 1 including a distance sensor.
 11. The fixture of claim1 including a light level sensor.
 12. The fixture of claim 1 including amotion sensor.
 13. The fixture of claim 1 including a crowd densitysensor.